With rapid development of computer technologies and network technologies, a signal transmission rate becomes increasingly higher, and requirements on output accuracy and reliability of a board power supply also become increasingly higher. In addition, increasingly more electronic components are integrated on the board power supply, and therefore a processing technique is complex. In a board power supply development or production phase, board power supplies that undergo a strict test by a manufacturer still have a specific failure rate. Even though some board power supplies pass an automatic test equipment (ATE) check, a specific percentage of the board power supplies become faulty soon.
In a whole-machine test phase of an electronic device, an online voltage adjustment circuit for a board power supply is used to adjust an output voltage of the board power supply to implement secondary filtering of the board power supply, thereby ensuring relatively strong stability of the board power supply when a range of the output voltage of the board power supply is relatively large, to be specific, ensuring that a design of the board power supply has a specific margin. In an adjustment process, a bias resistor is welded on a feedback (FB) pin of the board power supply. A resistance value of the bias resistor is adjusted such that the FB pin obtains different FB values, and further the board power supply outputs different voltages.
In the foregoing board power supply adjustment process, the bias resistor needs to be manually welded. This is time- and labor-consuming, poor welding easily occurs, and an operation process is complex.